How to reduce noise radiation from explosion-proof motors

Sources of explosion-proof motor noise

When mechanical equipment is running, the friction, impact or unbalanced force between parts causes mechanical parts and shells to vibrate irregularly and radiate noise. When explosion-proof motors are operating, they often generate the following noises:

1. The motor rotor will also generate noise when it vibrates;

2. The operation of the bearing will also produce noise;

3. The brush and the commutator make noise due to friction contact;

4. Noise caused by vibration of the end cover due to bearing vibration;

Measures to reduce noise radiation

1. Mechanical noise. Mechanical noise is mainly caused by the vibration or mutual impact of the moving parts of the engine during operation due to the periodic changes in gas pressure and inertia force. It has the characteristics of long-distance noise transmission and low attenuation.

2. Combustion noise: Combustion noise is the structural vibration and noise generated during the combustion of diesel.

3. Air intake noise. The function of the air intake channel is to ensure the normal operation of the engine and create good heat dissipation conditions for the unit itself. The air intake channel of the unit must allow the air to enter the machine room smoothly, but at the same time, the mechanical noise and airflow noise of the unit will also radiate outside the machine room through this air intake channel.

4. Cooling fan and exhaust noise. The fan noise of the unit is composed of eddy current noise, rotation noise and mechanical noise. Exhaust noise, airflow noise, fan noise and mechanical noise will be transmitted through the exhaust channel, thus causing noise pollution to the environment.

5. Try to design explosion-proof motors to be short and thick. Considering the reduction of sound radiation, short and thick motors are more advantageous than thin and long ones.

6. Add damping measures. For example, fill damping materials such as aluminum powder or epoxy resin between the iron core and the base.

7. Improve the elasticity of the connection between the stator core and the base. This is mainly for large and medium-sized motors, where the base and the core are connected together with the help of longitudinal ribs.

8. Transmission noise of foundation vibration. The strong mechanical vibration of the diesel engine can be transmitted to various places outdoors through the foundation over a long distance and then radiate noise through the ground.